1. Technical Field
The present invention relates to a technical field of electro-optical devices such as liquid crystal devices and of electronic apparatuses having the electro-optical devices, such as liquid crystal projectors.
2. Related Art
In a case that a liquid crystal device, which is an example of the electro-optical devices, is used as a light valve of a liquid crystal projector, intense light from a light source is condensed and incident on the liquid crystal device for projecting an enlarged image on a screen. The incidence of such intense light from a light source raises the temperature of the liquid crystal device and, thereby, the temperature of a liquid crystal interposed between a pair of transparent substrates of the liquid crystal device, resulting in deterioration of properties of the liquid crystal. In order to solve such a problem, for example, JP-A-8-76109 (Patent Document 1) discloses technique of preventing a liquid crystal device from increasing in temperature due to infrared light. That is, a mirror having a low reflectivity of infrared light is integrated into an optical system of a liquid crystal projector, and thereby an infrared light component is eliminated from light incident on the liquid crystal device.
Furthermore, if dirt or dust (hereinafter simply referred to as “dust”) is adhered to the surface of a light valve, the image of the dust is also projected on a projection screen. Therefore, the image quality may be decreased. Consequently, many liquid crystal devices additionally have dust-proof substrates on the outer surfaces of substrates for the liquid crystal devices.
However, in the technique disclosed in Patent Document 1, since a mirror having a low reflectivity of infrared light is integrated into an optical system of a liquid crystal projector, miniaturization of the optical system is difficult compared to that of a liquid crystal device not having such a mirror. Thus, there is a technical problem that miniaturization of the liquid crystal projector is difficult. In addition, extra cost for manufacturing such a mirror makes it difficult to decrease the manufacturing cost of the liquid crystal projector.